// Copyright (c) 2011 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "base/sys_info.h"

#include <stddef.h>
#include <stdint.h>

#include <limits>

#include "base/files/file_util.h"
#include "base/lazy_instance.h"
#include "base/logging.h"
#include "base/numerics/safe_conversions.h"
#include "base/strings/string_number_conversions.h"
#include "base/sys_info_internal.h"
#include "build/build_config.h"

namespace {

int64_t AmountOfMemory(int pages_name)
{
    long pages = sysconf(pages_name);
    long page_size = sysconf(_SC_PAGESIZE);
    if (pages == -1 || page_size == -1) {
        NOTREACHED();
        return 0;
    }
    return static_cast<int64_t>(pages) * page_size;
}

int64_t AmountOfPhysicalMemory()
{
    return AmountOfMemory(_SC_PHYS_PAGES);
}

base::LazyInstance<
    base::internal::LazySysInfoValue<int64_t, AmountOfPhysicalMemory>>::Leaky
    g_lazy_physical_memory
    = LAZY_INSTANCE_INITIALIZER;

} // namespace

namespace base {

// static
int64_t SysInfo::AmountOfAvailablePhysicalMemory()
{
    return AmountOfMemory(_SC_AVPHYS_PAGES);
}

// static
int64_t SysInfo::AmountOfPhysicalMemory()
{
    return g_lazy_physical_memory.Get().value();
}

// static
std::string SysInfo::CPUModelName()
{
#if defined(OS_CHROMEOS) && defined(ARCH_CPU_ARMEL)
    const char kCpuModelPrefix[] = "Hardware";
#else
    const char kCpuModelPrefix[] = "model name";
#endif
    std::string contents;
    ReadFileToString(FilePath("/proc/cpuinfo"), &contents);
    DCHECK(!contents.empty());
    if (!contents.empty()) {
        std::istringstream iss(contents);
        std::string line;
        while (std::getline(iss, line)) {
            if (line.compare(0, strlen(kCpuModelPrefix), kCpuModelPrefix) == 0) {
                size_t pos = line.find(": ");
                return line.substr(pos + 2);
            }
        }
    }
    return std::string();
}

} // namespace base
